A couple years ago I bought an Al Stohlman Tandy round knife. It wasn't even close to the condition he describes in his 'Use and Care of Hand Tools' - type book, and I only made it much worse trying to sharpen it by hand. So I built a "Thing". I work in the aerospace industry for a living, so I had a pretty good idea of where I wanted to end up, and knew that I would fall far short of that level working in my garage with hand tools. I used a piece of 2" x 2' x 1/4" angle iron, and put a lot of thought and work into it. I used the Lansky sharpening system idea, basically, working up to their finest stone, and quit (for now) with their leather strop.
I originally put this idea up on a 'Facebook' page, and took a lot of flack about it not being perfect, or exactly equal throughout the entire curve of the blade, etc, Some of the people commenting were big names in the sharpening business, and they definitely know what they were talking about. The thing that they didn't get was that I just wanted something that would work for my occasional project, and I leave my pursuit of perfection behind at the company's door when I leave my job in aerospace for the day, and go home to work on stuff. I stole my motto in life from Theodore Roosevelt..."Do what you can, with what you have, where you are". I think it turned out great, because now I can cut caiman tails so fine that when you hold the cut edges together, it's hard to see where you caused the separation.
(I haven't been on this site in a long time, so I'm not being rude if I don't respond to questions. I don't have any type of instructions, never made a single drawing, or anything like that. The only important thing that I can tell you is that I did my trigonometry calculations to come up with a 15 degree angle on the blade. Like I said, I have an Al Stohlman knife, but you can customize it to whatever you have. I feel that the key to this device is that it is very repeatable, within a small margin of error. I'm very happy with the results, and figure that I put much less time into making it than I would have spent trying to teach myself the muscle memory necessary to get proficient at sharpening by hand.)